[Koha] unable to install koha on ubuntu 12.04

I am using Ubuntu 12.04 server.I tried to install koha using sudo apt-get install koha-common but it is showing unable to locate the package koha.plz help me -- View this message in context: http://koha.1045719.n5.nabble.com/unable-to-install-koha-on-ubuntu-12-04-tp5... Sent from the Koha-general mailing list archive at Nabble.com.